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<H1 id="MPI_Comm_dup_with_info">MPI_Comm_dup_with_info</H1>
Duplicates an existing communicator using the supplied info hints 
<H2>Synopsis</H2>
<PRE>
</PRE>
<PRE>
int MPI_Comm_dup_with_info(MPI_Comm comm, MPI_Info info, MPI_Comm *newcomm)
</PRE>

<P>
<H2>Input Parameters</H2>
<DL>
<DT><B>comm </B> <DD> communicator (handle)

<DT><B>info </B> <DD> info object (handle)
</DL>
<P>
<H2>Output Parameters</H2>
<DL>
<DT><B>newcomm </B> <DD> copy of comm (handle)
</DL>
<P>
<H2>Notes</H2>
MPI_Comm_dup_with_info behaves exactly as MPI_Comm_dup except that
the info hints associated with the communicator comm are not
duplicated in newcomm.  The hints provided by the argument info are
associated with the output communicator newcomm instead.
<P>
<H2>Info hints</H2>
<DL>
<DT><B>mpi_assert_no_any_tag </B> <DD> boolean, default = false.
If set to true, user promises that MPI_ANY_TAG will not be used with the
communicator. This potentially allows MPICH to treat messages with different
tags independent and seek to improve performance, e.g. by employ multiple
network context.
</DL>
<DL>
<DT><B>mpi_assert_no_any_source </B> <DD> boolean, default = false.
If set to true, user promises that MPI_ANY_SOURCE will not be used with the
communicator. This potentially allows MPICH to treat messages send to different
ranks or receive from different ranks independent and seek to improve
performance, e.g. by employ multiple network context.
</DL>
<DL>
<DT><B>mpi_assert_exact_length </B> <DD> boolean, default = false.
If set to true, user promises that the lengths of messages received by the
process will always equal to the size of the corresponding receive buffers.
</DL>
<DL>
<DT><B>mpi_assert_allow_overtaking </B> <DD> boolean, default = false.
If set to true, user asserts that send operations are not required to be matched
at the receiver in the order in which the send operations were performed by the
sender, and receive operations are not required to be matched in the order in
which they were performed by the receivers.
</DL>
<P>
<H2>Thread and Interrupt Safety</H2>
<P>
This routine is thread-safe.  This means that this routine may be
safely used by multiple threads without the need for any user-provided
thread locks.  However, the routine is not interrupt safe.  Typically,
this is due to the use of memory allocation routines such as <tt>malloc
</tt>or other non-MPICH runtime routines that are themselves not interrupt-safe.
<P>
<H2>Notes for Fortran</H2>
All MPI routines in Fortran (except for <tt>MPI_WTIME</tt> and <tt>MPI_WTICK</tt>) have
an additional argument <tt>ierr</tt> at the end of the argument list.  <tt>ierr
</tt>is an integer and has the same meaning as the return value of the routine
in C.  In Fortran, MPI routines are subroutines, and are invoked with the
<tt>call</tt> statement.
<P>
All MPI objects (e.g., <tt>MPI_Datatype</tt>, <tt>MPI_Comm</tt>) are of type <tt>INTEGER
</tt>in Fortran.
<P>
<H2>Errors</H2>
<P>
All MPI routines (except <tt>MPI_Wtime</tt> and <tt>MPI_Wtick</tt>) return an error value;
C routines as the value of the function and Fortran routines in the last
argument.  Before the value is returned, the current MPI error handler is
called.  By default, this error handler aborts the MPI job.  The error handler
may be changed with <tt>MPI_Comm_set_errhandler</tt> (for communicators),
<tt>MPI_File_set_errhandler</tt> (for files), and <tt>MPI_Win_set_errhandler</tt> (for
RMA windows).  The MPI-1 routine <tt>MPI_Errhandler_set</tt> may be used but
its use is deprecated.  The predefined error handler
<tt>MPI_ERRORS_RETURN</tt> may be used to cause error values to be returned.
Note that MPI does <em>not</em> guarantee that an MPI program can continue past
an error; however, MPI implementations will attempt to continue whenever
possible.
<P>
<DL>
<DT><B>MPI_SUCCESS </B> <DD> No error; MPI routine completed successfully.
</DL>
<DL>
<DT><B>MPI_ERR_ARG </B> <DD> Invalid argument.  Some argument is invalid and is not
identified by a specific error class (e.g., <tt>MPI_ERR_RANK</tt>).
</DL>
<DL>
<DT><B>MPI_ERR_COMM </B> <DD> Invalid communicator.  A common error is to use a null
communicator in a call (not even allowed in <tt>MPI_Comm_rank</tt>).
</DL>
<DL>
<DT><B>MPI_ERR_INFO </B> <DD> Invalid Info 
</DL>
<DL>
<DT><B>MPI_ERR_OTHER </B> <DD> Other error; use <tt>MPI_Error_string</tt> to get more information
about this error code. 
</DL>
<P>
<H2>See Also</H2>
 MPI_Comm_dup, MPI_Comm_free, MPI_Keyval_create, MPI_Attr_put, MPI_Attr_delete, MPI_Comm_create_keyval, MPI_Comm_set_attr, MPI_Comm_delete_attr
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